THE EVOLUTION OF THE PEIMATES 333 many of their organs because they adopted different modes of life. From a study of palaeontology we must confess that the actual common ancestor of Man and the large Apes is still as unknown as it was in Darwin's day; and it will be long before we can definitely point to it. We are unable to say with certainty that any of the Siwalik fossils is the common ancestor. But we know that none of the existing Apes is in the direct line of Man's descent. Man is supreme in the Animal Kingdom. He surpasses the Apes in being bimanous and bipedal, in his power of articulate speech and in his complex psychology. He has attained this position, while retaining many primitive features, in virtue of his large neopallium.